How To Update Jailbreak And Unlock iOS 6.0.1 iPhone 3GS

Straight to the point.
Warning! If you are on new baseband week 36 2010 then don't install iPad baseband
1. Download iOS 6.0.1 and 6.0 for your iPhone 3GS
2. Connect your phone to your PC and fire up iTunes (latest version)
3. Hold down the Shift Key of your keyboard and then click Restore. Select iOS 6.0.1 you downloaded for your device
4. Once iTunes finish installing your new OS, close it
5. Download Redsn0w 0.9.15b3
6. Extract to your desktop and run as administrator
7. Click Extras and click on Select IPSW
8. Select the iOS 6.0 you downloaded NOT the 6.0.1
9. Click OK and if you have a new bootrom 3GS click Yes if not Click NO
10. Go back and then select Jailbreak. Make sure Install Cydia is checked
Redsn0w will work is magic.
After jailbreak is complete, click Done
11. Go back click Extras and manually select IPSW again (6.0)
12. Now click on Just boot
If you get the missing error, just go back, disconnect your device from PC, exit redsn0w, plug in back and run Redsn0w in administrator mode. Select IPSW again and then go boot tethered.
13. Place your device in DFU mode by following the instructions
14. Redsn0w will again do its work and and your iPhone will boot up.
15. Once booted, head over to Cydia, click User and Done.
16. After Cydia first installing it's dependencies, go to Manage and then sources. Click on Edit and then Add (top-left screen)
17. Add source http://repo.iparelhols.com

That's it!

If you are on a Baseband like 06.15.00 and upgraded to 6.0.1. There's a possibility of "No Service" issue.

Just go to Extras, Select IPSW and select the 6.0 IPSW.
go back and then click on Jailbreak. Check install Cydia and then downgrade baseband to 05.13.04 for a network unlock with Redsn0w.
Once the downgrade is finished, boot up your device and then go to Cydia to install ultrasn0w fixer and then ultrasn0w.
Once you have installed this two packages your network bars should show up.

If all go successfully, you will be thanking me for this post.
However, if you are confused and not getting it wrong, leave a comment and I will attend to you.